Matthew Henry Commentary Matthew 16:5-12

"And the disciples came to the other side and forgot to take bread. And Jesus said unto them, Take heed and beware of the leaven of the Pharisees and Sadducees. And they reasoned among themselves, saying, We took no bread. And Jesus perceiving it said, O ye of little faith, why reason ye among yourselves, because ye have no bread? Do ye not yet perceive, neither remember the five loaves of the five thousand, and how many baskets ye took up? Neither the seven loaves of the four thousand, and how many baskets ye took up? How is it that ye do not perceive that I spake not to you concerning bread? But beware of the leaven of the Pharisees and Sadducees. Then understood they that he bade them not beware of the leaven of bread, but of the teaching of the Pharisees and Sadducees." — Matthew 16:5-12 (ASV)

Christ speaks of spiritual things using a comparison, and the disciples misunderstand him, taking his words to refer to carnal things. He was displeased that they should think him as concerned about bread as they were, and that they should be so unfamiliar with his way of preaching. Then they understood what he meant. Christ teaches by the Spirit of wisdom in the heart, opening the understanding to the Spirit of revelation in the word.